Hi, What is the difference between Schwann's Cells, myelin sheath and neurilemma? Does Schwann's cells produce the myelin sheath, and the myelin sheath surrounds the axon, kind of, but what does the neurilemma do? Does it wrap the myelin sheath? Thanks! ...

... "horn". It is %100 Keratin. Also, true horns do not branch but the American Pronghorn Atelope has forked horns that consist of a keratin sheath and a bony core....sounds like a horn right? BUT they shed them once a year. I think we may need some new terms for several species!